One of the challenges which we face today in terms of renewable energy is the mismatch between when this energy is generated and when it is needed. In order to make the most of the energy generated by renewables, such as wind and solar, flexibility is needed in the electricity grid. Heavyweight buildings can provide this flexibility by allowing for consumer energy demand to be shifted in time by using structural thermal energy storage.

Thermal mass has traditionally been used to improve the energy efficiency of buildings and provide a stable indoor temperature. A further - previously untapped – benefit is to use the thermal storage capacity offered by the structure to provide flexibility in energy grids and boost the uptake of renewable energy.